Structure and function of Halice hesmonectes (Amphipoda : Pardaliscidae) swarms from hydrothermal vents in the eastern Pacific

• Published in: Marine biology Vol. 136; no. 5; pp. 901 - 911
• Main Authors: SHEADER, M, VAN DOVER, C. L, SHANK, T. M
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 16-06-2000; Berlin Springer Nature B.V
• Subjects: Animal and plant ecology; Animal behavior; Animal reproduction; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Crustaceans; Demecology; Fundamental and applied biological sciences. Psychology; Halice hesmonectes; Low temperature; Marine; Marine biology; Pacific Ocean; Protozoa. Invertebrata; Pacific Ocean; Mid-ocean ridges; ISE, East Pacific Rise, Venture Hydrothermal Field; East Pacific Rise; Environmental factor; Population structure; Amphipoda; Crustacea; Marine environment; Aggregation; Sex ratio; Hydrothermal vent; Life cycle; Arthropoda; Developmental stage; Invertebrata
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s002270000300

Swarms of the pardaliscid amphipod Halice hesmonectes were sampled at low-temperature hydrothermal vents in the Venture Hydrothermal Fields of the East Pacific Rise. In excess of 3000 individuals were collected from a range of sites/habitats, and at two points in time (December 1991 and March 1994). The structure of swarms was described in terms of growth stages, the development of primary and secondary sex characteristics and the accumulation of nutritional reserves. The results demonstrated that swarms contained a wide range of growth stages, but that small juveniles and mature males and females were absent. Swarm structure was interpreted as an equilibrium dependent on the relative proportion of time spent by each growth stage in the swarm habitat. This equilibrium swarm structure was very similar at different sites and times. Swarms dominated by small juveniles occurred at the northern sites in December 1991 following a period of eruption and new venting in April 1991. Equilibrium swarm structure had become re-established at these sites by March 1994. The function of swarming was considered. The results indicated that swarming was not associated with reproductive activity. The available evidence, though not conclusive, suggested that swarms were associated with feeding.